I believe the answer is B, an extended metaphor.
It can't be A because similes are comparing two unlike things using the words "like" or "as", which will also eliminate D.
It can't be C because a personification is where an inanimate object is given human-like qualities.
Throughout the entire passage, the author compares Ben to a bear and uses words such as "growled", "barked", "lumbered" which shows how the comparison between the two is prolonging throughout the passage.
What are the options?
Is there any under the question?
The underlined phrase is an example of which of these poetic devices?
C. Alliteration